New Chips Arrive, But DX4/75 Sticks Around

Ed Perratore

Notebooks based on Intel's 75-MHz 486DX4 CPU are popular with users who require multimedia capabilities on the road for presentations or light teleconferencing. But if you heed the hoopla over 100-MHz DX4s and even Intel's brand-new 75-MHz, 3.3-V Pentiums, you might be tempted to skip the DX4/75.

That may not be wise. If you're in the market for a feature-rich notebook, you'll find that 100-MHz DX4-based notebooks are just arriving from a few top-tier vendors due to a relative scarcity of the processor. The lack of 100-MHz DX4s is an issue of priorities--in Intel's 0.6-micron manufacturing process, the higher-priced Pentiums have priority. ``DX4s are losing out to Pentiums in [Intel's assembly] lines,'' says Steve Andler, director of mobil e-computing products marketing for AST Research.

At press time, AST had decided not to introduce a 100-MHz DX4 notebooks because it wasn't sure it would receive enough chips to meet its demand. IBM, however, planned to debut four DX4/100 models in early October.

But although Pentiums are edging out DX4s on the production line, Pentiums have typically been found in desktops, not portables. The first notebooks based on 5-V Pentiums suffered from short battery life and required fans or liquid cooling techniques to prevent overheating.

When 3.3-V P54C chips are readily available for notebooks (90- and 100-MHz versions should ship in volume this year), some notebook vendors say that they will design systems that are ventilated well enough not to subject users to fan droning.

According to Toshiba, its 3.3-V, 75-MHz P54C-based T4900CT, which is slated to ship in mid-November, won't need a fan to disperse heat, thanks to the company's experience with tab bonding. Toshiba says that Intel h as implemented tape-carrier packaging that reduces the volume of the CPU packaging. When the packaging is tab-bonded to the motherboard, the chip dissipates heat quickly.

Even when the Pentium chips are available, top-tier notebook vendors may still wait to introduce systems. One reason is that vendors haven't yet tapped all the potential buyers of the DX4/100. Price is another consideration.

Prior to Intel's planned pricing changes this fall, DX4/75s cost $429 each (in quantities of 1000), DX4/100s $516, and P54C/90 $707. At press time, Intel hadn't released prices for the P54C/75, but the DX4 notebooks may look more attractive than the first notebooks based on the 75-MHz Pentium if battery life is more important than performance. When vendors design Pentium systems to improve power management and ventilation and incorporate PCI (Peripheral Component Interconnect), users needing full-motion video or other compute-intensive tasks from their notebooks may never look back. Or at least, they'd bet ter not have to. ``If you're willing to pay a premium for a Pentium notebook,'' says Altounian, ``you don't want marginal differences in performance.''